JSFiddle - React, Tailwind, and code Playground

HTML

<ol id="main_ol">
    <li>Sales</li>
    <ol>
        <li>North</li>
        <li>South</li>
    </ol>
    <li>Support</li>
    <ol>
        <li>Pc</li>
        <li>Mac</li>
    </ol>
    <li>Accounts</li>
</ol>

JavaScript

//add to the end of the list
$('#main_ol').append('<li>a</li>');

//remove support list item
$('#main_ol li:eq(3)').remove();